There’s just no getting around the fact that solving some of the world’s most persistent animal diseases can get a bit bloody. That’s quickly obvious in a visit to the Bustad Hall necropsy suite run by the Washington Animal Disease Diagnostic Lab.

Veterinarians on this visit are performing necropsies—animal autopsies, if you will—on three bighorn sheep that state wildlife workers shot outside Vantage. Veterinarians want to see if they have been exposed to a bacterium suspected in the pneumonia killing sheep in the Yakima River canyon.

Photo courtesy of Barry Maas

“Not a real pretty place,” is how Charlie Powell, a vet school spokesman, describes the lab as he brings me and the Northwest News Network’s Anna King into a nearby viewing room. There lie three plainly dead bighorn sheep, their horns not all that big, the floor beneath them stained with wide streaks of blood. Over the next half hour or so, veterinarians and students essentially take the animals apart. They disarticulate a shoulder, cut through the ribs with long-handled pruning shears, remove organs, draw blood and gingerly bag sample upon sample of tissue.

It’s as if they are stripping a car for this accessory and that while leaving the bulk of the parts on a sheep rug. It isn’t exactly gross, and if you think it is you probably haven’t read this far. But it is literally morbid—these things are dead. And it is truly fascinating, particularly when one’s gaze moves to a quarter horse being dissected directly in front of the viewing room window.

Here is an animal so huge it has to be brought in on the room’s two-ton electric hoist, and it is unfolded to reveal a study of anatomy writ large—huge ribs, big liver, big intestines. Out of this, veterinarians can home in on the smallest, most banal killer. In this case, Jim Stanton, a clinical assistant professor, taps along the intestine and points out a hard section. A student slices it open and pulls out a softball-sized bolus. Better than a smoking gun, it is the soft, fibrous bullet that caused the colic that felled the horse.

WSU pathologists are now analyzing the sheep samples for an even smaller nemesis: Mycoplasma ovipneumoniae. WSU researchers found the bacterium in bighorn sheep from Hells Canyon just a couple of years ago, says Tom Besser, a professor of veterinary microbiology. They’re now finding signs of it in herd upon herd of pneumonia-plagued bighorn sheep. Besser says he doesn’t know if it is in this herd yet, “but that’s what I’m going to look for.”